
Traffic-aware without load balancing (TwithoutLB): In this policy, the workload at each BS can be only allocated to the nearest BS with edge servers. Many existing server placement policies fall into this category [1]}, [2]}, [3]}, [4]}, [5]}, [6]}, [7]}, [8]}, [9]}. In this paper, we use k-means algorithm to group BSs into \(k\)  clusters, and assign all the workload in each cluster to the centroid of this cluster. Let \(l_i\)  be the total workload of the BSs in the \(i\) -th cluster. Place \(K\frac{l_i}{\sum _{i=1}^k l_i}\)  servers at the centroid of the \(i\) -th cluster.

Traffic-aware with load balancing (TwithLB): In this policy, the workload at each BS can be load balanced to the close-by BSs. This setting was also adopted in [10]}, [11]}, [12]}, [13]}. Here, we compute a server placement solution by solving (REF ) with only one workload vector. (We use historical average workload vector in the evaluation.)

